Grease gun



Aug. 11, 1931. l P. GREssER *GREASE GUN Filed Aug. 31, 1929 m T N E V m Feier Grasser* /l ffl' ATTQRNEYf Patented Aug. 11, 1931 unir-En stares ears-Nr oFF-ica i GREASE Grinv r l Application. filed August 3K1, 1929. Serial I\Tov.r3 89,6 `26.A

My.` invention` relates to 1 improvements. in.

ai grease gun andf lubricating means having particular; reference to. hearingsfor motor.-

vehicles.

Aufl object;y of? they present invention f is the delivery ofi a predetermined; quantity ofn lubricant on eaclroperationand novel meansy fort first trapping the lubricant in acorn fined volume, kand then, by a. continuousI 10- strokepf the=plungerof the gunforcing it into ,the bearing;

A4 further object of my. invention.y isthe provision of; novel meansof preventing any return Howl of the Another; object of: my invention is; the

provision l ofi such. a structure that is .cheap to manufacture and? easy to assemble.`

y With these and; other objects in', view L aetniakeithe body or; receiver oflv the devicein the; formI of a, cylinder having a. piston slid:-

ably, mounted therein. One side of: the pis-f ton.; forms; a, chamber.A forL containing the lubricantrand; at; the other. side isi-mounted a aspringwhichcauses thepiston to exert pres;-Y sure constantly on theilubricant. An outlet chamber, disposed axially` of the cylinderf having screwthreaded engagement theretois` in communication with the lubricantI cham? .S0-ben by. means of: a. valved connection, and therefore receives. lubricant therefrom under.

pressure.

Ai pistonon the end ofthe ejectingplung-` er moves in a cylindrical extension portion.

Soff the chamber, within certain limits and thusmeasures the .amount of lubricant which` may; be discharged into `the outletr chamber 4 lcating hollow headedi cup shaped spring grease after it hasbeen, 151 ejected by the piston.

. stroke.

pressed valve,H permitting the lubricantto flow into the cylindrical. andmainportions of:` said outletchamber in advance ofl the piston. 4This valve is adapted to closevwhen the smallrpiston is-moved-for the purpose of expellingl the,1 lubricant andto open on the suction stroke-of said piston.

The invention is fully disclosed by way of example in the following description and in the Aaccompanyingdrawings, in which-' Figure 1 represents -a longitudinal section of: the gun vin its normal inactivel position, coupledjftothe-vnozzle andiitting shown in elevation; p

Ffgure-2f isracross sectional view cor responding to Figure 1, illustrating the smaillpistonY at the end ofits discharge I ,teferenceto these?views'willV now be madeby use oflikie characters which are employed to designate corresponding parts throughout. f

The-bodyoffthe device comprises a cylinder y1 which tapers*- atf2' towards its outlet endsand is therefintlernally threaded at 3. A" hollow outlet member `4isscrewed into' the internally threaded outletfend 3, and saidr hollow outlet member tapers as at 5, andi protrudingfrom saidtapering portion is aA cylindricaL portion 6 disposedaxially of. the cylinderl. vSaid tapered portion 5 is provided with a seriesof ports 7. Mount;

edinsaid' hollow outlet mem-ber is a perforated'fthimble shaped'spring pressed valve 'I 85 normally heldin port-closing-position by alight compressionv spring 9', which abuts against a-sleave`101ha-vinga flanged portion i 10',Y held in said member as' hereinafter describedw Withinthe cylinder'l'is .av piston 11 normally forcing the lubricant-tcward the outlet endiofI the gunl by means of a'spring 1:21which-alsobears-against a cap 18 covering the' inlet end of the cylinder. Aj plunger rod 14 is slidably mountedV in the .sul

receive the end of the plunger 14 and whichV collar serves as an abutment for a comparatively strong spring 20 which surrounds the stem 17 and the cylindrical portion 6 of the outlet member, and is supported at its other` end upon the tapered portion 5 of saidoutlet member 4, and said springkretracts .theA

plunger 14, and the piston 18.

lVhen the gun is filled with grease and the piston 18 is withdrawn :to the position shown in Figure 1, the lubricant under pressure of the spring 12 passes through the ports 7, said pressure, aided by the suction stroke of the plunger, overcoming the pressure exerted by the small light spring 9, pushes the reciprocating valve 8 from its port-closing position, and serves to fill the cylindrical portion 6- and the outlet member 4 with grease. lVhen pressure'is applied to the handle ofthe plunger rod 14, the piston 18 is movedy from the'position shown in Figure 1 to that shown in Figure 2, and the pressure of the grease in the cylindrical portion (5 and the outlet member 4 forces the valve 8 to seal itself against the inclined portion 5 of the hollow member .4, thus preventing the 'inflow of greasethrough the ports 7, and thus delivering a predetermined quantity of grease.

The cylindrical portion 6 has an internally shouldered portion 6 against which the piston 18 abuts on the completion of its suction stroke and which prevents withdrawal,

of the piston from its cylinder by the retractive force exerted by the spring 20.

In order to provide a quick releasefor any grease around'stem 17, .upon the suction. stroke ofthe piston 18, a series of holes 2li aredrilled in the shouldered portion 6 of the cylinder 6. Y y

On the discharge end of the screwthreaded outlet member 4 is screweda coupling memyber or nozzle A 22 provided with'Y suitable coupling means, and being adapted to press against the flanged portion l0 of the sleev 10 thereby holding it in place. d Said iianged sleeve 10 is provided with a ball check valve23, having a valve seat 24, and spring 2.5, which spring is mounted between an internal flange 26 and the ball check valve andnormally closes said valve,

thus preventing a return flow of grease froml the nozzle, K .p i

Although a specific embodiment of the invention has been illustrated and described, it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention las indicated by the appended claims.

Vhat I claim is:

1. A grease gun comprising a cylinder -having a grease containing chamber, a spring pressed piston, a plunger rod slidable through saidl piston, lugs on said plunger rod to prevent its withdrawal through said piston, a second cylinder and a second piston slidable therein, operating means for said second piston cooperating with said plunger rod, ahollow outlet member having a taperingY portion supporting said second named cylinder and being engaged by the outlet end of the irst named cylinder, ports in said tapered portion of the outlet member coinmunicating with the grease containing chamber, ay perforated cup shaped valvemounted in said v*hollow outlet member, a spring,

adapted to normally hold said valve in port closing position, aY sleeve mounted in the opposite end of said outlet member having a spring pressed check valve mounted therein,

and means for holding said sleeve in the dis:l

charge fend of said hollow outlet member.

2. A grease gun comprising a cylinder having a grease containing chamber, aspring pressed piston, a-plunger rod slidable through said piston, lugs on said plu-nger;

rod to prevent its withdrawal through `said piston, a second cylinder and a second pis-v ton slidableftherein,"` operating meansp for said second piston .cooperating with said plunger rod, a hollow outlet-.member havinga' tapering portion supporting said second named 'cylinder and being engaged :by the f outlet end lof thefirst named cylinder, portsl in said tapered portion of the outlet member communicating with thegrease containingy chamber, a perforated cup shaped valve mounted in said hollow outlet member, a

spring adapted to normally hold said valve in yport closing position, a {ianged sleeve mounted in the opposite end of said 'outlet member having a spring. pressedcheck valve mounted therein, and a discharge nozzle en-` gaging said hollow outlet member .providedl with means adapted to hold said `flanged sleeve'in the outlet end of said hollow outlet member. e. y 'j' 3. A lgrease gun comprisingacylinder having a grease containing chamber,a spring able through saidpiston and provided with means'preventing its withdrawal through said piston, a recessed collar adapted to receive said plunger rod, a stem projecting from said Vcollar and having an enlarged endV acting as a second piston, a hollow outlet member engaged by the outlet end of` y the first named cylinder ,and provided withl pressed pistona plunger: rod slid a tapered portion supporting a second cylinder, in which said second named piston reciprocates, disposed axially of and extending into said first named cylinder, said second cylinder having an inwardly shouldered portion preventing the withdrawal of said second piston therefrom, ports communicating between the grease chamber and said hollow discharge member and permitting the flow of grease into said second cylinder, a spring around said stem and said second cylinder disposed between the recessed collar and the tapered portion of the hollow outlet member, a perforated cup shaped valve mounted in said hollow outlet member, a spring adapted to normally hold said valve in port closing position, a sleeve mounted in the discharge end of said hollow outlet member having a spring pressed check valve mounted therein, and means for holding said sleeve in the discharge end of said hollow outlet member.

4l. A grease gun comprising a cylinder having a grease containing chamber, a

, spring pressed piston, a plunger rod slidle through said piston and provided with means preventing its withdrawal through said piston, a recessed collar adapted to receive said plunger rod, a stem projecting from said collar and having an enlargedend vacting as a second piston, a hollow outlet member engaged by the outlet end of the first named cylinder' and provided with a into said first named cylinder, a reciprocating piston in said second named cylinder, a passageway between said secondv cylinder and said outlet member, a cone-shaped hollow cylindrical spring-pressed valve member concentrically pierced to permit said reciprocating piston to pass therethrough, serving to control the flow of lubricant fromvthe first named cylinder into the second named cylinder upon the suction stroke of said reciprocating piston and from the outlet member into the discharge nozzle upon the pressure stroke of said reciprocating piston.

In testimony whereof I aiiX my signature.

PETER GRESSER.

' tapered portion supporting a second cylf Gli y inder, in which said second named piston reciprocates, disposed axially of and extending into said first named cylinder, said second cylinder having an inwardly shouldered portion preventing the withdrawal of said second piston therefrom, ports communicating between the grease chamber and said hollow discharge member and permitting the flow of grease into said second cylinder, a spring around said stem and said second cylinder disposed between the recessed collar and the tapered portion of the hollow outlet member, a perforated cup shaped valve mounted in said hollow outlet member, a spring adapted to normally hold said valve in said port closing position, a flanged sleeve mounted in the discharge end of said hollow outlet member having a spring pressed check valve mounted therein, and a discharge nozzle engaging said hollow outletv member provided with means adapted to hold said flanged sleeve in the outlet end of said hollow outlet member.

5. A lubricating device comprising a cylinder, a hollow outlet member adapted for connection to a nozzle, valve means mounted in said outlet member adapted to prevent a return iow of lubricant therethrough, ports in said outlet member communicating directly with said cylinder, a second cylinder extending from the outlet member on the inner side of said ports and partially lli) 

